General Idea of Disk Quotas

Windows XP tracks disk quotas and manages disk usage on a per-user, per-volume basis. Windows XP tracks disk quotas for each volume, even if the volumes are on the same hard disk. Because quotas are tracked on a per-user basis, every user's disk space is tracked regardless of the folder in which the user stores files.
Disk Quota Characteristics

Disk usages is based on file and folder ownership	Windows XP calculates disk space usage for users based on the files and folders that they own. When a user copies or saves a new file to an NTFS volume or takes ownership of a file on an NTFS volume, Windows XP charges the disk space for the file against the user's quota limit.
Disk quotas do not use compression	Windows XP ignores compression when it calculate hard disk space usage. Users are charged for each uncompressed byte, regardless of how much hard disk space is actually used. This is done partially because file compression produces different degrees of compression for different types of files. Different uncompressed file types that are the same size might end up being very different sizes when they are compressed.
Free space for applications is based on quota limit	When you enable disk quotas, the free space that Windows XP reports to applications for the volume is the amount of space remaining within the user's disk quota limit.

How to configure a Disk Quota

You can enable disk quotas and enforce disk quota warning and limits for all users or for individual users.
If you want to enable disk quotas open the properties dialog box for a disk, click Quota tab, and configure the options that are described in Table 2-3 and shown in Picture 2-5.
Quota Tab Options Table 2-3

Enable Quota Management	Select this check box to enable disk quota management.
Deny Disk Space To Users Exceeding Quota Limit	Select this check box so that when users exceed their hard disk space allocation, they receive an Out Of Disk Space message and cannot write to the volume.
Do Not Limit Disk Usage	Click this option when you do not want to limit the amount of hard disk space for users.
Limit Disk Space To	Configure the amount of disk space that users can use.
Set Warning Level To	Configure the amount of disk space that users can fill before Windows XP logs an event, indicating that a user is nearing his or her limit.
Log Event When A User Exceeds Their Quota Limit	Select this option if you want Windows XP to log an event in the Security log every time a user exceeds his or her quota limit.
Log Event When A User Exceeds Their Warning Level	Select this option if you want Windows XP to log an event in the Security log every time a user exceeds the warning level.
Quota Entries	Click this button to open the Quota Entires For windows, in which you can add a new entry, delete an entry, and view the per-user quota information.

Figure 2-5 Use the Quota tab of the properties dialog box for a disk to set disk quotas for users.

To enforce identical quota limits for all users, follow these steps:
1. In Window Explorer, right-click the volume on which you want to set disk quotas, and the click properties.
"Windows opens the properties dialog box for the volume."
2. Click the Quota Tab.
3. Select the Enable Quota Management check box.
4. Select Deny Disk Space To Users Exceeding Quota Limit check box.
"Windows XP will monitor usage and will not allow users to create files or folders on the volume when they exceed the limit."
5. Click Limit Disk Space To. In the Limit Disk Space To text box and in the Set Warning Level To text box, enter the values for the limit and warning levels that you want to set.
6. Click OK.

To enforce different quota limits for one or more specific users, use these steps:
1. In Windows Explorer, right-click the volume on which you want to set disk quotas, and then click Properties.
"Windows Explorer opens the Properties dialog box for the volume."
2. Click the Quota Tab.
3. Select the Enable Quota Management check box.
4. Select Deny Disk Space To Users Exceeding Quota Limit check box.
5. Click Quota Entries.
6. In the Quota Entries For window shown in Figure 2-7, click the Quota menu, and then click New Quota Entry.
Figure 2-7 Use the Quota Entries For dialog box to enter quotas for specific users.

How to check the status of Disk Quotas

• A red traffic light means that disk quotas are turned off.
• A yellow traffic light means that Windows XP is rebuilding disk quota information.
• A green traffic light means that the disk quota system is turned on.

How to watch Disk Quotas

• Use Figure 2-7 to monitor disk space.

How to use Disk Quotas properly

• On the volume where Windows XP is installed, if you turn on disk quotas settings, and your user account has a disk quota limit, log on as Administrator to install additional Windows XP components and applications. In this way, Windows XP will not charge the disk space that you use to install applications against the disk quota allowance for your user account.
• You can monitor hard disk usage and generate hard disk usage information without preventing users from saving data. To do so, clear the Deny Disk Space To Users Exceeding Quota Limit check box when you enable disk quotas.
• Set more-restrictive default limits for all user accounts, and then modify the limits to allow more disk space to users who work with large files.
• If multiple users share computers running Windows XP, set disk quota limits on computer volumes so that disk space is shared by all users who share the computer.
• Generally, you should set disk quotas on shared volumes to limit storage for users. Set disk quotas on public folders and network servers to ensure that users share hard disk space appropriately. When storage resource are scarce, you might want to set disk quotas on all shared hard disk space.
• Delete disk quota entries for users who no longer store store files on a volume. You can delete quota entries for a user account only after all files that the user owns have been removed the volume or after another user has taken ownership of the files.